| URN |
etd-0804111-151732 |
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| Author |
Kai-Ping Lee |
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| Author's Email Address |
No Public. |
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| Statistics |
This thesis had been viewed 5582 times. Download 0 times. |
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| Department |
Materials and Optoelectronic Science |
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| Year |
2010 |
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| Semester |
2 |
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| Degree |
Master |
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| Type of Document |
|
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| Language |
zh-TW.Big5 Chinese |
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| Title |
Research of single crystal growth and scintillation performance of Ce:(Lu(1-X)YX)2SiO5(Ce:LYSO) scintillator |
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| Date of Defense |
2011-07-20 |
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| Page Count |
75 |
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| Keyword |
scintillation performance research
Ce:(Lu(1-x)Yx)2SiO5
Single crystal growth
Czochralski method
scintillation crystal
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| Abstract |
Single crystals of cerium doped lutetium yttrium orthosilicate scintillator (Ce:(Lu(1-X)YX)2SiO5; Ce:LYSO) were grown through Czochralski method to investigate the affection of different growth conditions on the crystal growth. The relationship between thermal field and crystal growth was investigated. Different growth parameters and insulating system were adopted and compared to decrease the temperature gradient. It is found that the new insulating bricks can decrease effectively the temperature gradient and solve the crack problem of grown crystal.
The relationship between materials ratio and the impurities in crystals. It is found that the optimized material ratio is Lu2O3:Y2O3:CeO2:SiO2=1.8563:0.1397:0.008:1.99. Under this ratio, we can get the crystals with best macroscopic optical quality.
The scintillation properties of grown Ce:LYSO single crystal were measured. Through comparing the data with those in published literatures, it is found that the grown Ce:LYSO crystals present outstanding optical transmission, reaching the theoretical value about 84% in the visible light region. The transmission, UV-excitation and emission spectra are almost identical with the reported ones.
The luminescence efficiency (LE) of random chosen 43 Ce:LYSO samples were measured on the γ-ray multi-channel energy spectrum. It is found that the Ce:LYSO samples present stable luminescence efficiency with minimum channel number 3636.37, maximum channel number 4293.78, maximum deviation of 9.91% and standard deviation of 152.24 (3.77%).
Annealing treatments were carried out in the air atmosphere on the small pieces of Ce:LYSO single crystals to eliminate the oxygen vacancies in the sample. It is found that the optimized annealing condition to improve the luminescence efficiency of Ce:LYSO is 1400 ℃, 80 h under air atmosphere. |
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| Advisory Committee |
Da-Ren Hang - chair
Jui-Hung Hsu - co-chair
Ming-Chi Chou - advisor
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| Files |
Indicate in-campus at 99 year and off-campus access at 99 year. |
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| Date of Submission |
2011-08-04 |
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